Largest chunk of Earth’s crust born out of odd tectonic circumstances
Jacques Descloitres/MODIS Rapid Response Team/GSFC/NASA
A three-way tectonic tango may have led to the birth of what is now the largest chunk of Earth’s crust.
By scrutinizing what little geologic evidence remains from 190 million years ago, researchers reconstructed the origins of the Pacific tectonic plate, which now covers a fifth of Earth’s surface. The plate formed during the early Jurassic period from a single point where three tectonic plates once met, the work suggests. The plate’s birthplace sat above the gravesite of a section of tectonic plate that sank into the planet’s depths, the researchers report July 27 in Science Advances. The remnants of that sunken plate remain embedded in Earth’s mantle.
This origin story of tectonic life and death is unique in Earth’s known history, says study coauthor Lydian Boschman, a geologist and geodynamicist at Utrecht University in the Netherlands. All of the other